Bug 2497410 - CVE-2026-9547 curl: curl: Man-in-the-middle attack via SSH host key bypass [fedora-all]
Summary: CVE-2026-9547 curl: curl: Man-in-the-middle attack via SSH host key bypass [f...
Keywords:
Status: NEW
Alias: None
Product: Fedora
Classification: Fedora
Component: curl
Version: rawhide
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
Assignee: Jan Macku
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard: {"flaws": ["ee76bccd-42cc-40c3-991b-b...
Depends On:
Blocks: CVE-2026-9547
TreeView+ depends on / blocked
 
Reported: 2026-07-06 17:59 UTC by Jon Moroney
Modified: 2026-07-06 17:59 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Type: ---
Embargoed:


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Description Jon Moroney 2026-07-06 17:59:50 UTC
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

When a libcurl-based application performs transfers via `SCP://` or `SFTP://`
and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an
untrusted server. This vulnerability occurs when a server presents a host key
type that does not match the specific key type already recorded for that host
in the `known_hosts` file. Instead of rejecting the mismatch, the callback
mechanism fails to properly enforce the restriction, allowing the connection
to succeed without warning and risking a potential man-in-the-middle attack.


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